utorak, prosinac 7, 2010

PDP Context Activation RejectionsBISS tech blog is all about GPRS and UMTS technology, events, procedures, gossip

and what's happening in this fast-changing world. You will also read what's happening

in the mobile world plus a whole range of topics in the IT world.

This blog was introduced, together with specific topics, in other to help users and

telecom operators to better understand necessary procedures in mobile world.

Our first topic is about errors that can cause PDP Context activation rejections.

Text below is brief description about attach and PDP activation procedure together

with most common rejection causes.

Read it carefully and do not hesitate to ask questions, we'll be glad to help to explain

each cause in more detailed manner.

For more information see the Reference list below.

Introduction

Session Management (SM) establishes, modifies and releases packet data

sessions with well defined QoS between UE and GGSN

Packet session attributes are called PDP contexts

A UE may have more than one PDP context simultaneously, each with a SM

protocol entity

PDP Context Contents PDP = Packet Data Protocol (generic name)

protocols to be used: IP (likely), X.25

Session Management Procedures SM procedures require existing GMM context

SM procedures are:

– PDP context activation

PDP address, QoS etc. are set

UE must be in PMM-CONNECTED state

– PDP context modification

QoS etc. is modified

UE must be in PMM-CONNECTED state

– PDP context deactivation

packet data session is released

PDP context also deactivated when UE moves to PMM-IDLE or PMM-DETACHED

state

PDP Context Activation by UE

Request (1) contains NSAPI, PDP type, QoS, PDP address (static, dyn.)

Reject may occur due to insufficient resources, unknown PDP address or PDP

type, unsupported or not subscribed options wished

Request (8) may occur if network does not offer requested QoS

PDP Context Activation by network

If HLR cannot determine a SGSN or the SGSN cannot find the UE with specified

IMSI, the PDP Context Activation Procedure fails (3.b, 5.b)

After the SGSN‘s request the UE performs the PDP Context Activation

Causes in PDP Context Activation Procedure:

In a request, the Cause Value indicates the reason for the request. The Cause shall be

included in the request message.

In a response, the Cause Value indicates the acceptance or the rejection of the

corresponding request. In addition, the Cause Value may indicate what was the

reason for the corresponding request. The Cause value shall be included in the

response message.

Cause values are shared with the GTP' protocol specified in 3GPP TS 32.295.

'Request accepted' is returned when a GSN has accepted a control plane request.

'Non-existent' indicates a non-existent or an inactive PDP context.

'IMSI not known' indicates a non-existent MM context.

'MS is GPRS Detached' indicates an idle MM context.

'MS is not GPRS Responding' and 'MS Refuses' may be used by SGSN to reject a

Network-Requested PDP Context Activation.

'Version not supported' is returned when the recipient does not recognize the version

number in the request message.

'Request IMSI', 'Request IMEI', 'Request IMSI and IMEI' and 'No identity needed' are

used by GGSN to notify SGSN what to do.

'No resources available' is a generic temporary error condition indicating that some

kind of resource is used up for that moment excluding the conditions all dynamic PDP

addresses are occupied and no memory is available.

'All dynamic PDP addresses occupied' indicates that the GSN does not have a free

dynamic PDP address to allocate any longer.

'No memory available' indicates that the GSN does not have enough memory to use.

'Service not supported' is a generic error indicated that the GSN do not support the

requested service.

'User authentication failed' indicates that the external packet network has rejected

the user's service request.

'System failure' is a generic permanent error condition.

'Roaming restriction' indicates that the SGSN cannot activate the requested PDP

context because of the roaming restrictions.

'P-TMSI Signature mismatch' is returned if either:

- the P-TMSI Signature stored in the old SGSN does not match the value sent by

the MS via the new SGSN; or

- the MS does not provide the P-TMSI Signature to the new SGSN while the old

SGSN has stored the P-TMSI Signature for that MS.

'Semantic error in the TFT operation', 'Syntactic error in the TFT operation', 'Semantic

errors in packet filter(s)' and 'Syntactic errors in packet filters(s)' and 'PDP context

without TFT already activated' are indications of abnormal cases involving TFTs.

The abnormal TFT cases and the use of the cause codes are defined in 3GPP TS

24.008.

'Invalid message format', 'Mandatory IE incorrect', 'Mandatory IE missing' and

'Optional IE incorrect' are indications of protocol errors described in the section Error

handling.

'GPRS connection suspended' indicates that the GPRS activities of the mobile station

are suspended.

'Authentication failure' indicates that the user authentication failed in the new SGSN.

'Context not found' indicates that the PDP Context referenced in an Active Secondary

Context Request message was not found in the receiving GGSN.

'Relocation failure' indicates that the SRNS relocation failed in the new SGSN side.

'Unknown mandatory extension header' signals in a response message that the

corresponding request included an extension header for which comprehension was

required but unknown to the receiving end.

'APN Restriction type incompatibility with currently active PDP Contexts' conveys to an

SGSN that a PDP Context was not allowed to be created or moved by the GGSN

because if it had been created or moved, the rules for PDP Context coexistence as

described in 3GPP TS 23.060, sub-clause 15.4, would have been broken.

'MS MBMS Capabilities Insufficient' is used by the SGSN to notify the GGSN that the

MS MBMS Bearer Capabilities are less than the Required MBMS Bearer Capabilities.

'MBMS Bearer Context Superseded' indicates that the SGSN has already established

an MBMS bearer plane with another GGSN.

'Invalid Correlation-ID' indicates that the Correlation-ID was already in use in the

SGSN.

The SM Cause information elements for radio side are shown in the Table 1.Table

1.

Cause

value

(dec)

Cause

value

(bits)

Cause

value

(hex)

Cause

25 00011001 19 LLC or SNDCP Failure

26 00011010 1A Insufficient Resources

27 00011011 1B Missing or Unknown APN

28 00011100 1C Unknown PDP Address or PDP Type

29 00011101 1D User Authentication Failed

30 00011110 1E Activation Rejected By GGSN

31 00011111 1F Activation Rejected, Unspecified

32 00100000 20 Service Option Not Supported

33 00100001 21 Requested Service Opt Not Subscribed

34 00100010 22 Service Opt Temporarily Out of Order

35 00100011 23 NSAPI Already Used

36 00100100 24 Regular Deactivation

37 00100101 25 QoS Not Accepted

38 00100110 26 Network Failure

39 00100111 27 Reactivation Required

40 00101000 28 Feature Not Supported

41 00101001 29 Semantic Error in TFT Operation

42 00101010 2A Syntactical Error in TFT Operation

43 00101011 2B Unknown PDP Context

44 00101100 2C Semantic Error in Packet Filter(s)

45 00101101 2D Syntactical Error inPacket Filter(s)

46 00101110 2E PDP Context Without TFT Already Activated

81 01010001 51 Invalid Transaction Identifier Value

95 01011111 5F Semantically Incorrect Message

96 01100000 60 Invalid Mandatory Information

97 01100001 61 Msg Type Non-existent/Non ImplementedState

98 01100010 62 Msg Type Not Compatible With Protocol State

99 01100011 63 IE Non-existent or Not Implemented

100 01100100 64 Conditional IE Error

101 01100101 65 Msg Not Compatible With Protocol State

111 01101111 6F Protocol Error, Unspecified

112 01110000 70 APN Restrict Value Incompatible Without PDP Context

Table 1. SM Cause Information Element

The MM Cause information elements for radio side are shown in the Table 2.

Table 2.

Cause

value (dec)

Cause

value

(bits)

Cause

value

(hex)

Cause

20000001

02 IMSI Unknown

30000001

13 Illegal MS

60000011

06 Illegal ME

70000011

17 GPRS Services Not Allowed

80000100

08 GPRS/Non-GPRS Services Not Allowed

90000100

19 MS Identity Cannot Be Derived By The Network

100000101

0A Implicitly Detached

110000101

1B PLMN Not Allowed

120000110

0C Location Area Not Allowed

130000110

1D Roaming Not Allowed In This LA

160001000

010 MSC Temporarily Not Reachable

170001000

111 Network Failure

220001011

016 Congestion

48-630011000

030-3F Retry Upon Entry Into A New Cell

950101111

15F Semantically Incorrect Message

960110000

060 Invalid Mandatory Information

970110000

161 Msg Type Non-existent/Non ImplementedState

980110001

062 Msg Type Not Compatible With Protocol State

990110001

163 IE Non-existent or Not Implemented

1000110010

064 Conditional IE Error

1010110010

165 Msg Not Compatible With Protocol State

1110110111

16F Protocol Error, Unspecified

Table 2. GMM Cause Information Element

The SM Cause information elements on core side for radio side are shown in the Table

3.

Table 3.

Cause

value

(dec)

Cause

value

(bits)

Cause

value

(hex)

Cause

192 11000000 C0 Non-existent

193 11000001 C1 Invalid message format

194 11000010 C2 IMSI not known

195 11000011 C3 MS is GPRS Detached

196 11000100 C4 MS is not GPRS Responding

197 11000101 C5 MS Refuses

198 11000110 C6 Version not supported

199 11000111 C7 No resources available

200 11001000 C8 Service not supported

201 11001001 C9 Mandatory IE incorrect

202 11001010 CA Mandatory IE missing

203 11001011 CB Optional IE incorrect

204 11001100 CC System failure

205 11001101 CD Roaming restriction

206 11001110 CE P-TMSI Signature mismatch

207 11001111 CF GPRS connection suspended

208 11010000 D0 Authentication failure

209 11010001 D1 User authentication failed

210 11010010 D2 Context not found

211 11010011 D3 All dynamic PDP addresses are occupied

212 11010100 D4 No memory is available

213 11010101 D5 Relocation failure

214 11010110 D6 Unknown mandatory extension header

215 11010111 D7 Semantic error in the TFT operation

216 11011000 D8 Syntactic error in the TFT operation

217 11011001 D9 Semantic errors in packet filter(s)

218 11011010 DA Syntactic errors in packet filter(s)

219 11011011 DB Missing or unknown APN

220 11011100 DC Unknown PDP address or PDP type

221 11011101 DD PDP context without TFT already activated

222 11011110 DE APN access denied – no subscription

223 11011111 DFAPN Restriction type incompatibility withcurrently

active PDP Contexts

224 11100000 E0 MS MBMS Capabilities Insufficient

225 11100001 E1 Invalid Correlation-ID

226 11100010 E2 MBMS Bearer Context Superseded

227 -

240

11100010

-

11110000

E3 - F0 For future use

241 -

255

11110001

-

F1 - FF Cause values reserved for GPRS chargingprotocol use

11111111 (see GTP' in 3GPP TS 32.295)

Table 3. SM Cause Information Element on GTP protocol